c_std/ and throw()

[Benjamin Kosnik]

I think we all agree that this cfns.gperf mechanism is the way to do this 
kind of stuff. It's much cleaner that way.

Could you use something like the --enable-c99 flag that the library is 
using? Ie if the user actively wants C99 support and configures with it, 
then the extra C99 functions are added to cfns.gperf. That seems to match 
the way the library is now configured.

I don't see a way to turn this on and off on the command line. I'm 
historically bad at seeing ways to do things that way though.

-benjamin

> Yes, but I think it should be controllable by some -std flag.